Bladed rotors



D. J. CLARKE 3,077,297

Feb. l2, 1963 BLADED ROTORS 3 Sheets-Sheety 1 Filed Oct. 24, 1960 FIG-1- INVENTOR.

DANIEL J. CLARKE B www4/@fj ATTORNEYS D. J. CLARKE BLADED ROTORS Feb. 12, 1963 3 Sheets-Sheet 2 Filed Oct. 24, 1960 INVEN TOR.

DANIEL J. CLARKE Feb. 124, 1963 n. J. CLARKE 3,077,297

' BLADED RoToRs Filed oct. 24, 1960 3 Sheets-Sheet 3 FIG-lO INVENTOR.

Y DANIEL J. CLARKE ATTORNEYS Uited States Patent tice anims? ELADED RTORS Daniel 3. Clarita, Bay City7 Mich., assigner to The Stalker Corporation, Essent/ille, thv/lich., a corporation of Michllilcd @et 24, mail, Ser. No. 64,5% 6 Claims. (ill. 23d- 134) This invention relates to Iblade-cl composite rotors for fluid machines for interchanging force with a liquid and more particularly to a bladed rotor comprised of sheet material with the various components thereof bonded together.

In bladed rotors of centrifugal or mixed-flow types where the diameter of the hub is small compared to the diameter of the blade tips, it is ditlicult to provide a light weight brazed sheet metal construction since the radial extent of the Iblades is often too limited for brazing them with shear joints to the sheet metal hub components and the like.

This invention overcomes these difiiculties by providing a rotor including a plurality of spiders which are bonded together in axial relation and which have radially spaced legs of varying lengths. The legs are arranged to form chordwise sets of legs so positioned that blade shells can be fitted over each set and bonded thereto to support the shell, which denes the exterior surface of the blade. The varying terminal lengths of the spider legs provide rotor blades which are partially hollow and which are secured to a light weight hub formed by the composite of the hub elements of the several spiders. Since the blades are thus relatively light, the rotor hub does not carry as high centrifugal loads as when the blades are solid, and weight may therefore be saved in both the blades and the rotor hub with an overall saving of about lifty percent of the solid rotor weight.

t is therefore a principal object of this invention to provide a bladed rotor as outlined above which has a plurality of spiders forming partially hollow blades.

Another object of this invention is to provide ya bladed rotor as outlined above comprising a plurality of spiders with legs of varying lengths which support the rblade shells interiorly thereof.

A further object of this invention is to provide a bladed rotor as outlined above with a plurality of spiders which are spaced apart axially at their bodies or hub elements and which are bonded together to form a rotor hub.

Another object of this invention is to provide a bladed rotor as outlined above having components formed of light weight sheet material with blade shells and rim llanges supported on a plurality of spider legs forming a partially hollow interior.

ther obiects and advantages of the invention will be apparent from the Ifollowing descrip-tion, the accompanying drawings and the appended claims.

In the drawings- FIG. l is an axial section of a mixed-flow bladed rotor constructed according to this invention taken generally along the line Ll-l of FIG. 2;

FIG. 2 is a rear view of the rotor of FIG. l;

FIG. 3 is a fragmentary section through the rotor taken generally `along the line 3 3 of FIG. l with one of the blades being partially broken away to expose details of the interior thereof;

FIG. 4 is an axial view of a full spider used in the rotor;

FIG. 5 is an axial View of a spider with the legs cut to dilferent lengths;

FIG. 6 is a fragmentary section through one of the blades taken generally along the line 6-6 of FiG. l;

FIG. 7 is another fragmentary section through the same blade taken generally along the line 7-7 of FIG. l;

FIG. 8 is a further fragmentary section through the blade taken generally along the line S-S of FIG. l;

FIG. 9 is a fragmentary section taken generally along the line 9-9 of FIG. l showing the trailing edge of the blade;

FIG. l0 is a partial axial section showing the employment of this invention in a purely centrifugal iiow bladed rotor;

FlG. l1 is a front view, partially in section, showing details of the internal arrangement of the components of the rotor of FIG. l0; and

FIG. 12 is a section through one of the blades taken generally valong the line 12-12 of FIG. 1l.

Referring to the drawings, which illustrate preferred embodiments of the invention, a mixed axial and centrifugal llow bladed rotor constructed in accordance with this invention is indicated generally at l@ in FIGS. l and 2. The rotor 1d includes a plurality of stamped sheet metal spiders suc-h as indicated at l2 and i3 in FIGS. l, 4 and 5. The spider-s 12 and 13 are each. formed with a body or central hub element l5 through which an yaxial opening i6 is formed. The spider l2 of FIG. 4 is formed with a plurality or" radially extending, relatively narrow legs 18 of equal length spaced peripherally of the hub element l5. The spider 13 of FIG. 5 is formed with a plurality of radially extending, relatively narrow legs Ztl-23 which are formed with differing terminal lengths, the lengths thereof being arranged serially in descending and ascending relation about the element i5.

Hub means for the rotor includes a plurality of the spiders l2 and I3 placed in axial alignment one to the other and bonded together by fused metal, `as by brazing, thereby forming a strong light weight rotor hub 25'. T-he adjacent spiders I3 have their legs arranged in rows to form generally chordwise sets 39' of legs with varying radial lengths at dilerent chordwise positions. Preferably, each successive spider along the axial length of the hub is positioned l/ n of a circle from the preceding spider where n equals the number of blades, thus providing balance and uniformity, and evenly spacing th-e'legs of differing lengths spanwise of the blades.

Several of the spiders l2 may be employed interspersed among the spiders I3, but preferably only one spider l2 is employed at the leading edge of the blades. Thus, its legs 18 form the first or front leg in each. of the sets of legs. Also, the end portions of the longest legs Ztl may be ground down or otherwise shortened to conform to the outer radial edge contour of the blade adjacent the leading edge, as indicated at 3l in FG. 5. Further, in blades of the character described, the trailing edge of the blade contour is often tapered as indicated at 33 in PEG. l. Therefore, suitable spiders 13 for use at these stations are formed by severing a portion of the longer legs 2li as shown by the broken lines 3i in FIG. 5.

The spiders include means on each leg presenting a bonding surface for substantial lapping engagement with the interior surface of a hollow sheet metal blade shell do fitted over the sets 3d of legs thereby forming brazing surfaces for the attachment of the sets to such a blade shell. This is preferably accomplished by forming the legs with a twist, in the case of the mixed-flow rotor I@ of FlGS. 1 and 2, as shown in FIGS. 4 and 5. The blade shell Il@ is fitted over the legs of each of the sets of legs and is bonded thereto at the outer exposed surfaces il of the legs as shown in FIGS. 6 8. The trailing edges 4d of the blade shell are preferably brought together and bonded as shown in FIG. 9 to form the trailing edges of the blades.

Means closing the open spaces between. the blades at their hub end portions include rim dange means in the form of spacers 45 extending Ibetween adjacent pairs of Patented Feb. l2, lt'

' blades.

the blades. The spacers may be formed with upwardly turned anges d6 which are bonded to the sides of the Preferably, the vhub 3d includes one or more generally circular auxiliary supporting disks 5t) positioned between the spiders having an outer surface Si proportioned to engage the rim flanges d5 along their peripheral inner surface for the additional support of the flanges.

Preferably, a majority of the spiders are formed as indicated in FIG. 5 'so as to keep 4the cost of the stamping dies to a minimum. But many of the spiders which are positioned adjacent the leading edge of the blades have legs which are shortened as necessary to confine them to the interior dimensions of the blade shell as described above. The arrangementof the sets 3@ of legs results in some of the legs terminating radially short of the outer radial edge ofthe blades. Also, thehub elements terminate radiallyA short of the rim flanges, thereby providing hollow spaces 52. resulting in a partially hollow blade construction. i

The rotor lil is preferably provided with a hub `disk 55 having an outer flanged surface 56 conforming to the inner peripheral surface of the rim ilanges 'Ll-5.V The hub disk 55 is bonded at its surface and at theV hub y elements l5 to the rotor and is provided with a central opening'57 coaxial with the openings 16 in the spiders within which a shaft 6 9 may be xed thereto by fused metal or by any ofthe well-known methods.

The embodiment shown in FGS. -12 illustrates the employment of this invention with a purely radial flow bladed rotor. The rotor is shown as including a plurality of spiders 70, similar to the spiders 13 described above, with hub elements 71 bonded together in contiguous axial relation forming a rotor hub '72. The legs 74 `of the spiders are arranged to form sets of legs in the manner described above, with the longer legs of the spiders ernployed adjacent the leading edge being shortened to conform to the radial outline of the blade.

This embodiment illustrates a bladed rotor having l6 blades, and it is understood `that each of the spiders has legs corresponding in number to the number of blades. This embodiment further dilers from the preceding embodiment inthe arrangement of the blade shells 78 which are formed with integral rim flange portions 80. The adjacent blade shells 78 are brought together and bonded at the radial terminal edges thereof as shown at 8l. in FIG. ll, and the backs 34 of the shells are, in turn, bonded to an annular support disk 85. In this embodiment, the spider legs '74 are radially straight and formed without a twist to present surfaces for bonding engagement with the adjacent inner wall surfaces of the vblade shells 7S.

The rim flange portions 80 are preferabiy supported by one or more auxiliary suporting disks 36, a pair of which are shown as employed in this invention having outer peripheral surfaces proportioned to engage the blade shells 7% at the inner surfaces of the rim flange portions Sil. Also, an annular hub disk 87 may be employed having a hub portion 3S in bonded relation to the adjacent disk and having outer ilange portions 9i) and 91 bonded to the inner surfaces respectively of the rim flange portions 8d of the blade shell and the suport disk 85.

The varying lengths of the legs 74 of the supporting spiders provides hollow spaces @2 in the blades and between the rim flange portion 30 and the hub elements 7l thereby resulting in a partially hollow bladed rotor structure having considerably less weight than its solid metal counterpart.

lt is therefore seen .that this invention provides a bladed rotor construction which combines high strength with low weight. The radial extent of the bonded surfaces between the sets of legs and the adjacent blade shells provides a considerable shearing surface for support of the shell under very high centrifugal loads. Use isrnade as much as possible of identical components in theform of identical spider stampings, thereby resulting in a cost savings. The varying length of the leg within each of the sets of legs provides a partially hollow blade structure while, the hub elements combine to form an extremely strong rotor hub.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention which is dened in the appended claims.

What is claimed is:

1. A substantially radial flow partially hollow bladed rotor, comprising a plurality of sheet metal spiders each having a central hub element and each having a plurality of radially extending legs spaced peripherally of said clement with peripherally spaced adjacent legs having differing terminal radial lengths, means fixing a plurality of said spiders inaxial contiguous relation to each other at said hub elements to form a substantially solid rotor hub with the relative position of said legs changing chordwise from blade to blade to form generally chordwise sets of legs with varying radial leglengths at different chordwise positions, and a blade shell positioned over eachsaid sets of legs and bonded thereto forming a plurality of open spaces between .said shells and said sets.

V2. A lsubstantially lradial flow partially hollow bladed rotor, comprising a plurality of substantially identical stamped sheet metal spiders having a central hub element and each having a plural-ity of radially extending relatively narrow legs spaced peripherally of said element, the adjacent legs on each of said spiders having differing radial lengths, a plurality of said spiders being bonded together in axial relation at said hub elements forming a substantially solid rotor hub with each of said spiders being rotated by an amount proportional to the spacing of said legs providing chordwise sets of legs with differing radial leg lengths at different chordwise positions, and a hollow sheet metal blade shell positioned over each said sets of legs and bonded thereto forming a plurality of open spaces between said shells and said sets.

3. A substantially radial ilow partially hollow bladed rotor, comprising a plurality of su-bstantially identical relatively thin spiders, each spider having a centrally disposed hub element and n integral radially extending legs spaced peripherally of said hub element and the legs of each of said spiders being formed with progressively differing terminal radial lengths where n equals the number of rotor blades, means fixing a plurality of said spiders in axial relation at said hu-b elements to form a rotor hub -with each successive spider being rotated l/It of a circle from the preceding spider forming generally chordwise sets of legs having uniformly varying radial lengths at different chordwise positions, means on said legs presenting a bonding surface for engagement with the interior surface of a blade shell, a hollow blade shell positioned over each said sets of legs and bonded thereto at said bonding surfaces forming a plurality of open spaces between said shells and said legs, and rim flange means extending between adjacent pairs of blades spanwise of said blades in forming a hollow space between the root ends of said blades and said hub elements.

4. A partially hollow bladed rotor having a substantially radial ow, comprising a plurality of relatively thin spiders formed of sheet vmaterial having a centrally disposed hub element and a plurality of integral radially extending relatively narrow legs spaced peripherally of said hub element and being formed with differing terminal lengths, means fixing a plurality of said spiders in axial relation at said hub elements to form a rotor hub, the legs of said spiders arranged to form generally chordwise sets of legs having varying radial lengths at diierent chordwise positions, means on said legs presenting a bonding surface'for engagement with the interior surface of a blade shell, a hollow sheet metal blade shell positioned over each said sets of legs and bonded thereto at said bonding surfaces forming a plurality of open spaces between said shells and said legs, and rim `flange means extending between adjacent pairs of blades spanwise of said blades from an inlet adjacent said hub and tapering radially outwardly with increasing radii rearwardly along the rotor axis forming a hollow space between the rOOt ends of said blades and said hub elements.

5. A partially hollow bladed rotor comprising a plurality of metal spiders having a central hub element and a plurality of radially extending legs spaced peripherally of said element and being formed with diiering terminal lengths, means fixing a plurality of said spiders in axial relation at said hub elements to form a rotor hub, the legs of said spiders arranged to form generally chordwise sets of legs with differing radial lengths at different chordwise positions, a blade shell positioned over each said sets of legs and bonded thereto forming a plurality of open spaces between said shells and said sets, rim flanges connected to said blade shells and extending between adjacent pairs of blades spanwise of said blades, and at least one annular auxiliary supporting disk positioned in axial relation to said spiders and having an outer peripheral surface proportioned to engage the inner surface of said rim flanges intermediate the ends thereof for the support of said lianges in spaced relation to said hub elements.

6. A partially hollow bladed substantially radial ow rotor comprising a plurality of substantially identical stamped sheet metal spiders having a central hub element and a plurality of radially extending legs spaced peripherally of said element and being formed with diftering terminal lengths, means fixing a plurality of said spiders in axial rotated relation at said hub elements to form a rotor hub with the legs of said spiders arranged to form generally chordwise sets of legs with differing radial lengths at different chordwise positions, means on said legs forming a bonding surface for engagement with the interior surface of a blade shell, a hollow sheet metal blade shell positioned over each said sets of legs and bonded thereto at said bonding surfaces forming a plurality of open spaces between said shells and said sets, sheet metal rim flanges connected to said blade shells and extending between adjacent pairs ot Ablades spanwise of said blades and extending from an inlet adjacent said hub rearwardly with increasing radii along the rotor axis, and at least one annular auxiliary supporting disk positioned in axial relation to said spiders and having an outer peripheral surface proportioned to engage the inner surface of said rim anges for the support of said llanges in spaced relation to said hub elements.

References Cited in the iile of this patent UNITED STATES PATENTS 2,344,444 Malczewski Mar. 14, 1944 2,618,462 Kane Nov. 18, 1952 2,786,646 Grantham Mar. 26, 1957 2,889,107 Stalker June 2, 1959 FOREIGN PATENTS 317,371 Germany Dee. 22, 1919 OTHER REFERENCES Publication-NASA. (Memo l0-558E), Structural Design and Preliminary Evaluation of a Lightweight, Brazed, Air-Cooled Turbine Assembly, Dec. 5, 1958. 

1. A SUBSTANTIALLY RADIAL FLOW PARTIALLY HOLLOW BLADED ROTOR, COMPRISING A PLURALITY OF SHEET METAL SPIDERS EACH HAVING A CENTRAL HUB ELEMENT AND EACH HAVING A PLURALITY OF RADIALLY EXTENDING LEGS SPACED PERIPHERALLY OF SAID ELEMENT WITH PERIPHERALLY SPACED ADJACENT LEGS HAVING DIFFERING TERMINAL RADIAL LENGTHS, MEANS FIXING A PLURALITY OF SAID SPIDERS IN AXIAL CONTIGUOUS RELATION TO EACH OTHER AT SAID HUB ELEMENTS TO FORM A SUBSTANTIALLY SOLID ROTOR HUB WITH THE RELATIVE POSITION OF SAID LEGS CHANGING CHORDWISE FROM BLADE TO BLADE TO FORM GENERALLY CHORDWISE SETS OF LEGS WITH VARYING RADIAL LEG LENGTHS AT DIFFERENT CHORDWISE POSITIONS, AND A BLADE SHELL POSITIONED OVER EACH SAID SETS OF LEGS AND BONDED THERETO 